TY - GEN
T1 - Terahertz detectors based on vacuum electronics
AU - Buchmann, Tobias Olaf
AU - Sebek, Matej
AU - Kawai, Naoya
AU - Katsuyama, Kota
AU - Lange, Simon J.
AU - Jepsen, Peter Uhd
PY - 2023
Y1 - 2023
N2 - We report on various metasurfaces for the purpose of THz driven electron field emission and subsequent detection using vacuum electronics. The underlying principle is based on strong localised field enhancement at metal and semimetal emission points, which bends the vacuum potential temporarily to allow for field emission of electrons from the parent material. The structures are investigated for varying electric field strength using electron time-of-flight measurements as well as electron multiplication and visualisation on a phosphor screen. Measured properties include the emitted electron energy, their count, and the emission threshold. From the recorded data, the local field enhancement for each structure is extracted and compared to simulated values. Subsequently, optimised metasurfaces are implemented into handheld devices that serve as easy-to-use THz detectors. These devices include photomultiplier tubes which operate at frequencies from THz to infrared, as well as live imaging devices with kilohertz framerates. The investigated metallic structures include standard dipole antennas, double split-ring resonators, bow-tie designs, hybrid split-ring and dipole designs, and logarithmic spirals. Semimetallic structures are based on structured and unstructured graphene, which show different emission characteristics. All samples are investigated using strong-field THz radiation generated using lithiumniobate tilted pulse front setup, as well as commercial THz-TDS instruments. In conclusion, we present a holistic overview of the current state-of-the-art THz-PMTs and image intensifiers.
AB - We report on various metasurfaces for the purpose of THz driven electron field emission and subsequent detection using vacuum electronics. The underlying principle is based on strong localised field enhancement at metal and semimetal emission points, which bends the vacuum potential temporarily to allow for field emission of electrons from the parent material. The structures are investigated for varying electric field strength using electron time-of-flight measurements as well as electron multiplication and visualisation on a phosphor screen. Measured properties include the emitted electron energy, their count, and the emission threshold. From the recorded data, the local field enhancement for each structure is extracted and compared to simulated values. Subsequently, optimised metasurfaces are implemented into handheld devices that serve as easy-to-use THz detectors. These devices include photomultiplier tubes which operate at frequencies from THz to infrared, as well as live imaging devices with kilohertz framerates. The investigated metallic structures include standard dipole antennas, double split-ring resonators, bow-tie designs, hybrid split-ring and dipole designs, and logarithmic spirals. Semimetallic structures are based on structured and unstructured graphene, which show different emission characteristics. All samples are investigated using strong-field THz radiation generated using lithiumniobate tilted pulse front setup, as well as commercial THz-TDS instruments. In conclusion, we present a holistic overview of the current state-of-the-art THz-PMTs and image intensifiers.
U2 - 10.1117/12.2681570
DO - 10.1117/12.2681570
M3 - Article in proceedings
SN - 9781510665804
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Proceedings of SPIE
PB - SPIE - International Society for Optical Engineering
T2 - SPIE Optical Engineering + Applications 2023
Y2 - 20 August 2023 through 25 August 2023
ER -